correct, find an engineer and ask him for solid answers.
best we can do is give personal experiences which might not be the same as what your engineer thinks

for instance you only realy need to upgrade your brakes to deal with the extra weight not the power. so standard stanza brakes or the s13 silvia brake setup would be fine. but then other engineers require you to fit a booster...dont know why, but they do
and some will want even bigger brakes